The present invention falls within a family of inventions by the inventor such as those described in U.S. Pat. No. 6,554,596 entitled “FLUID TURBINE DEVICE” issued Apr. 29, 2003 and U.S. patent application Ser. No. 10/680,236, entitled “ROTARY PISTONS”. These inventions essentially relate to rotary pistons, motors and pumps having encased rotors with radially extending vanes which move in and out of the rotors, depending on their location within the casing. The vane movement in and out of the rotor is at least partly achieved by cam surfaces within the casing. The walls of the casing are not of uniform radius, and are formed so as to facilitate movement of the vanes and flow of fluid between inlet and outlet ports in the casing.
Also of background interest is the inventor's co-pending U.S. application Ser. No. 10/791,287 entitled HINGED PADDLE PUMP, that application describing and illustrating a rotary, positive displacement pump for fluids having a plurality of paddles secured to the rotor in equally spaced, similarly contoured pockets, for movement between an extended position with a portion of the paddle extending outwardly beyond the cylindrical surface of the rotor and a retracted position wherein the paddle is seated entirely within its corresponding pocket. Each paddle and pocket are configured so that when the paddle is in retracted position, it provides an interior surface which conforms to the cylindrical surface of the rotor and closes the pocket, and between that position and the extended position, it bears against the interior side wall of the housing while still closing the pocket. The paddles are biased outwardly but allowed to move towards retracted position under urging of the interior side wall during operation of the device.
It is an object of the present invention to provide an alternative construction of pump which will have a variety of applications including moving heavy fluids or fluids with solids in them.